Process for producing paraffinic oils



Feb. 25, 1941. F, FREY HAL 2,233,363

PROCESS FOR. PRODUCING PARAFFINIC OILS Filed June 2'7, 1936 2 Sheets-Sheet 1 a) v M FREDERICK E. FREY ,7 PAUL V. MCKINNEY NVENTOR.

WILLIAM H. WOOD A TTORNEYS.

Feb. 25, 1941. F. E. FREY ETAL 2,233,363

PROCESS FOR PRODUCING PARAFFINIC OILS Filed June 27, 1936 2 Sheets-Sheet 2 FREDERICK E. FREY PAUL V. MCKINNEY INVENTORS WILLIAM H. WOOD BY 1 f ATTORNEYS.

Patented Feb. 25, 1941 Frederick E. Frey, Paul v. mxiriiimmswmnm Bartlesville, Okla,

11. Wood, Phillips Petroleum Delaware assignorsto Company, a corporation of Application June :1, 1936, Serial No. 87,190

7 Claims.

This invention relates to the manufacture of parafllnic and saturated hydrocarbon oils, and. more to the production of c oils suitable for motor fuel by catalytic synthesis from hydrocarbons of lower molecular weight.

The conversion of normally gaseous olefins into valuable hydrocarbons of higher molecular .weight, suitable for motor fuels, has been eifected 10 by heat and pressure, and the use of elevated complete conversion at temperatures below the pyrolysis range. The polymerization may also be effected with the aid of suitable catalysts at temperatures lower than those required for the purely thermal conversion;

either case, composed of varying proportions of hydrocarbons 'of several. types, a large P rtion being olefinic or unsaturated. Such oleiinic polymers may be converted into oils of saturated type by means of hydrogenation preferablyof the non-destructive type.

The present invention is an improvement of the invention set forth in Frey's application Serial No. 731,920, filed June 22, 1934, which issued May 21, 1935, as Patent 2,002,394, and also is an 5 improvement of the invention set forth in Freys copendi applimtion Serial No. 12,981 filed March 25, 1935, which is a continuation-in-part of the aforesaid application and which issued January 4, 1938, as Patent No. 2,104,296.

It is an object of the present invention to effect a process for the formation of predominantly saturated oilsat relatively low temperatures, below those required for producing such oils by thermal means, or at appreciably lower pressures, with resultant saving in plant comtruction and operating expense, by effecting catalytieally the polymerization reactions which involve the direct union of and olefins of lower molecular weight than the oils to be produced.

A further object of this invention is to provide a process for the production of oilsof ementially saturated type without the step of hydrogenating partly olefinicpolymer oils.

A still further object is to provide a process for the conversion of of low molecular 'weight into oils of higher molecular weight without the intermediate conversion into simple olefinic hydrocarbons prior to eifecting conversion into oils.

Other objects will be apparent upon a further consideration of the following description of this invention.

The normally gaseous olefins,

- propylene, and the butylenes maybe converted in the process, constituting our invention, together with propane and butane which are normally gaseous, and pentanes. The conversion of co pentanes, and paramns of somewhat higher ethylene, I

pressures effecting rapid reaction and nearly,

The hydrocarbons of higher molecular weight which result, are, in

known polymerization catalysts under new and appropriate conditions and in novel pr ployed. Zinc chloride, zinc bromide, hydrous molecular weight, is desirable in circumstances in which their volatility is undesirably high. It will be understood that by es of low molecular weight 'is meant those which may yield by union with olefins, oils boiling within the gasoline range.

We have found that the union of with olefins to produce saturated hydrocarbons of higher molecular weight can be effected with 10 which will be presently described. Catalysts effective for the reaction are aluminum'chloride chemically combined with an equimolar quantity, more or less, of lithium, sodium, calcium, or potassium chloride, and the corresponding double compounds in which chlorine is replaced by bromine. Other modifying agents added to aluminum chloride or bromide may also be em- 20 alumina, and hydrous alumina deposited on or combined with hydrous silica. are likewise effective for catalyzing the reaction. The catalyst is conveniently used in granular form or disposed on an inert granular support. We have found that oils of a saturated type may be produced by'reacting together a mixture of parafllns with olefins, provided the ratio of olefins to is low in the mixture subjected to the action of the catalyst, and our process provides means whereby extensive and practical conversion may be obtained by passing the hydrocarbon stream into contact with the catalyst while maintaining a reaction temperature and while adding olefin in small proportion a plurality of times in the course of the reaction, addition of olefin taking place prior to contact with the catalyst in each addition, whereby added olefin is consumed prior to each subsequent addition of additional olefin. The concentration of olefin present throughout the reaction is in this way maintained at a low value, and thee reactants at a high value. The temperature of the reaction is somewhat'higher than the optimum for the familiar catalytic poiymerimtion 4- involving union of olefin with olefin, andwill ,vary from to about 400 1)., the lower temreaction. Pressures of 400 to 2500 pounds per square inch are preferable in most cases. With high olefin contents, exceeding 30%, the paraflins enter into reaction to only a limited degree, and the oils produced are} largely of the familiar una saturated type. Accordingly, we maintain olefin concentrations below 20%, and preferably below 10%, in order to obtain efflcient cooperative reaction of paraflins and olefins. Olefin concentrations in the paraihnic reactant-s as low as 0.5% may be maintained economically in the presence of the catalyst by making small olefin additions a sufliciently great number of times in the course of the reaction. The time of residence in the catalyst zone will vary with the manner of disposing catalyst in the reaction chamber and with the particular catalyst employed as will also the temperature of reaction, and both can be readily determined by experiment. The oils produced by this process are predominantly paraflinic, containing 20% or less of unsaturated hydrocarbons and distilled almost wholly in. the gasoline range, that is, below 225 C.

Figure 1 illustrates diagrammatically one form of apparatus for efiecting the present process, and, Figure 2 illustrates diagrammatically a modified form of apparatus for efiecting the process.

present invention will be readily understood from a consideration of Figure 1 01 the attached drawings, and the following description relative thereto. A stream of paraflinic hydrocarbons of low molecular weight is charged to the apparatus 11- lustrated diagrammatically in Figure, 1. by introducing ,the same by way of conduit l through which the hydrocarbons pass to the pump I I and are thereby forced to the heater I2 wherein they are brought to a reaction temperature. The desired degree of heat may be maintained in the heater I2 by any suitable heating means, such as heating coils'which may be provided with a feed pipe l3 and an outlet pipe 'I 4.

From the heater I2 the stream of paraffinic hydrocarbons flows through the conduit I5 to the plurality of catalyst chambers I6, II, I8, I9, 20,

' and 2| which are arranged in series. Portions of the catalyst chambers I6 and I1, I8 and I9, and and 2| are connected by the conduits 22, 23, and 24 respectively; while other portionsof the catalyst [chambers I1 and I8, and I9 and 20 are connected by the conduits and 26 respectively. A conduit 21 connects conduit 24 with conduit I5 adjacent the chamber-|6, and also connected to the conduit 21 are the conduits 28, 29 andv 30.

which connect with conduits 22, 23 and 24 respectively, and the conduits 3| and 32 which connect with the conduits 25 and 26 respectively.

Normally gaseous olefins are introduced into" the system through conduit 33 and are forced by the pump 34 to the conduit 21 through which the normally gaseous olefins-flow to the conduits 28, 29 and 30 to be introduced by conduits22, 23 and 24 into the catalytic chambers I'I, I9, and 2| respectively. From conduit 21 the olefins also flow through conduits 3|, and 32 into the conduits 25 and 26 to be introduced into the catalyst chambers I6 and 20. Conduit 21 also conducts olefins directly to conduit I5, from which they flow into the catalyst chamber I6.

Thus it wilrbe appreciated that a reaction between the parafflnic hydrocarbons introduced into the process by way of conduit I0, and the olefinic The operation of the process constituting this that of the paraflin and the olefin.

hydrocarbons introduced by way of conduit 33,

takes place in the several catalyst chambers I6,

I'I, I6, I9, 20 and 2| through which the reacting parafllnic and olefinic hydrocarbons flow in series. The reacting parafllnic and olefinic hydrocarbons after reaching the last catalyst chamber 2| pass therefrom through the conduit 35 into a separator 36 wherein oils of a higher molecular weight are separated and discharged from the process through the conduit 31 controlled by the valve 36.

Unreacted parafllns oi. low molecular weight and containing a small amount of olefin willpass from the separator 36 through the conduit 39, and will be forced by the pump 40 into theconduit I5 to be passed to the first catalyst chamber I6 and the succeeding ones as described.

The parafl'lns of low molecular weight most suitable for the process, namely'propane, butane,

pentanes and somewhat heavier 'parafllns may contain paraflins of lower olecular weight, and may be derived from petroleum, natural gas, or cracking still gases and other sources. Oleflns may be derived from cracking still gases, from pyrolysis of petroleum distillates and gases, and from dehydrogenation of ethane, propane, and butane. The product of catalytic partial dehydrogenation, containing unconverted parafin to.-

gether with the corresponding olefin is particularly suitable for conversion in our process, since both paraflln and olefin are present. Such a mixture of paraflin and olefin may be introduced through conduit 33 of Figure 1 as olefinic stock.

The olefin depletedparaflin recovered in separator 36 may be returned through conduit 39 to serve as the parafllnic reactant, and unconverted paraffins in excess are discharged through conduit 4| by opening'valve 42 and thereafter may be subjected to partial dehydrogenation and returned once more to the process by any suitablemanner not shown. This process is most advantageously applied to the conversion of propane and butane. The reacting of an individual paraffin with an individual olefin yields an oil of relatively simple composition predominating in saturated hydrocarbons whose molecular weight Example 1 isobutane was passed at 3,000 pounds per square inch pressure and 200 (3. through a tube containing 10 cc. of granular pumice (14-20 per inch mesh) coated with a catalyst prepared by melting together equimolar quantities of sodium chloride and anhydrous alumlnumfcliloride. A volume of isobutylene equal to 10% of the isobutane was divided into four streams and introduced into the catalyst tube at four equidistantfpoints, the rate of flow of the hydrocarbon being such that the time of passage through the catalyst zone occupied 10 minutes. The eilluents had the following composition:

As the analysis shows, the quantity of isobutane consumed was approximately equal to the isois the sum of.

butylene' consumed. The oils formed were almost wholly parafilnic in character and predominated in material distilling in the heptane-octane range. Figure 2 illustrates diagrammatically a modifled apparatus for effecting the present invention, and herein hydrocarbons, consisting of oleflns and paraflins, which are to'be reacted, enter the process together with each other through the conduit 50 and are forced by the pump 5| through the conduit 52 to the reaction chamber 53 wherein the hydrocarbons, comprising paraflins and oleflns, are brought into contact with a catalyst suitable for effecting the desired polymerization reaction.

Thereacted hydrocarbons are discharged from the chamber 53 into the conduit 54 and are divided into two streams, one of which flows through valve 55A into conduit '55 and is forced by pump 56 through valve 553 back into conduit 52 to be reintroduced into the reactionchamber 53. The other stream of reacted hydrocarbons flows through valv'e 51A and into conduit 51 passa ing into the separator 58 wherein the hydrocartrolled by valve 50.

Any unreacted gases will be predominately paraflinic and may be discharged through conduit 6|, and may be reacted with additional olefin or put to any other desired use.

However, it is to be understood that it may not always be desirable, or necessary, to recycle the reacted hydrocarbons from chamber 53 back through conduits 55 and 52 for'reprocessing in the reaction chamber, so therefore when desired, or conditions demand, the valves 55A and 55B, which are interposed in conduit 55, may be closed.

or it may be desirable, or necessary, to recycle the reacted hydrocarbons from chamber 53 back through the conduits 55' and 52 to the chamber again with only a minimum amount of the reacted hydrocarbons passing directly from the chamber 53 through conduits 54 and 51 to the separator 58, in such a case the valve 51A may be set at any desired partially closed position to limit the flow of the reacted hydrocarbons directly from chamber 53 to separator 58.

From the foregoing it should appear obvious that by control of valves 55A and 55B, and valve 51A the flow of the reacted hydrocarbons from the chamber 53 to the separator 58, or the recycling of these hydrocarbons back through the chamber 53 can be readily controlled and regulated.

We claim:

l. A continuous process for reacting paraiiins of low molecular weight with normally gaseous oleflns to produce predominantly paraifinic oils in the motor fuel boiling range and of higher molecular weight which comprises, bringing the paraflins into contact with a polymerization catalyst of the group zinc chloride, zinc bromide in a reaction zone for a suitable reaction period while maintaining a reaction temperature between 100 and 400 C. and a pressure of at least 100 pounds per square inch, introducing the normally gaseous oleflns .to the reaction zone a plurality of times during the reaction period while maintaining the concentration of added olefin present in the reacting hydrocarbons below 20 per cent, withdrawing the reacted hydrocarbons from the reaction zone and separating therefrom a hydrocarbon fraction containing the predominantly parafllnic oils in the motor fuel boiling range so produced.

2. A continuous process for reacting paraffins of low molecular weight with normally gaseous olefin hydrocarbons to produce predominantly paraflinic oils of high molecular weight in the motor fuel boiling range, which comprises passing a stream of hydrocarbons comprised of par-" saturated hydrocarbons present in the mixture does not exceed 20 per cent by weight of the total hydrocarbon stream and separating from /at least a portion of the eflluent of said reaction zone a hydrocarbon fraction comprising paraffinic oils in the motor fuel boiling range.

3. A continuous process for reacting paraflins of low molecular weight with normally gaseous olefin hydrocarbons to produce predominantly paraffinic oils of higher molecular weight in the motor fuel boiling range, which comprises passing a stream of hydrocarbon comprised of paraffins of low molecular weight in which normally gaseous olefin hydrocarbons are dispersed, while at a reaction temperature between 100 and 400 C. and a pressure greater than 100 pounds per square inch, through a reaction zone in the presence' of a polymerization catalyst of the group consisting of zinc chloride and bromide for a period of time such that reaction takes place consuming parafiln hydrocarbons and said olefin hydrocarbons, passing a portion of the eilluents of said reaction zone to be mixed with the hydrocarbon stream entering said zone and separating from another portion of said eflluents predominantly paraflinic oils of higher molecular weight in the motor fuel boiling range, so produced.

4. In a continuous process for producing predominantly paraffinic hydrocarbons of high molecular weight from paraflins and olefln of lower molecular weight, the steps which comprise maintaining a stream of predominantly paraflinic hydrocarbons in independent cyclic circulation through a reaction zone containing a polymerization catalyst of the group consisting of zinc chloride and bromide, and wherein a reaction temperature between 100 and 400 C. and a pressure between 100 and 3000 pounds per square inch are maintained and wherein a catalyzed reaction takes place consuming parafiin and added olefin hydrocarbons, introducing into said stream an olefin-containing hydrocarbon mixture such that the concentration of added, unreacted olefins does not exceed 20 per cent by weight of the total mixture local to the point of introduction, withdrawing from the said stream a portion thereof and separating therefrom predominantly paraflinic hydrocarbons of higher molecular weight.

5. In a continuous process for producing predominantly paraflinic hydrocarbons of higher molecular weight from parafiins and oleflns of lower molecular weight the steps which comprise maintaining a predominantly parafiinic hydrocarbon mixture in continuous circulation in an endless circulatory cycle which contains a reaction zone containing a polymerization catalyst of the group consisting of zinc chloride and bromide, and a zone of hydrocarbon introduction, adding a hydrocarbon mixture containing parafiins of low molecular weight having at least three carbon atoms per molecule and olefin hydrocarbons at the zone of hydrocarbon introduction thereby producing a hydrocarbon mixture such that the concentration of unreacted added olefin is between 0.5 and 20 percent by weight of the total hydrocarbon mixture, passing the mixture to said reaction zone wherein a catalyzed reaction takes place consuming parafllns and oleflns and forming paraflin hydrocarbons and maintaining therein a reaction temperature between 100 and 400 C. and a pressure'in excess of 100 pounds per square inch, passing the reacted mix ture back to the zone of hydrocarbon introduction thus completing the endless circulatory cycle, withdrawing at some point in, the cycle a portion of the mixture and separating therefrom predominantly parafiinic hydrocarbons of higher molecular weight.

6. A continuous process for reacting parafllns of low molecular weight with normally gaseous olefins to produce predominantly parafiinic oils in the motor fuel boiling range and of higher molecular weight which comprises bringing the paraflinstinto contact with a polymerization catalyst comprising zinc bromide in a reaction zone for a suitable reaction period while maintaining a reaction temperature between 100 and 400 C. and a pressure of at least 100 pounds per square inch, introducing the normally gaseous olefins to the reaction zone a plurality of times during the reaction period while maintaining the concentration of added olefin present in the reacting hydrocarbons below 20 per cent, withdrawing the reacted hydrocarbons from the reaction z'bne and separating therefrom a hydrocarbon fraction containing the predominantly parafilnic oils in the motor fuel boiling range so produced.

- 7. A continuous process for reacting paraifins of low molecular weight with normally gaseous olefins to produce predominantly parafilnic oils in the motor fuel boiling range and of higher molecular weight which com-prises bringing the parafllns into contact with a polymerization catalyst comprising zinc chloride in a reaction zone for a suitable reaction period while maintaining a reaction temperature between 100 and 400 C. and a pressure of at least 100 pounds per square inch, introducing the normally gaseous olefins to the reaction zone a plurality of times during the reaction period while maintaining the concentration of added olefin present in the reacting hydrocarbons below 20 per cent, withdrawing the reacted hydrocarbons from the reaction zone and separating therefrom 'a hydrocarbon fraction containing the predominantly paraflinic oils in the motor fuel boiling range 50 produced.

FREDERICK E. FREY. PAUL V. MCKINNEY. WILLIAM H. WOOD. 

